The invention relates to a safety device for the occupant of the central rear seat position in a motor vehicle.
Rear passengers who sit on the central section of the rear bench seat are in greater danger in the case of accidents than the occupants in other seat positions, in spite of the prescribed pelvic belt, because in the case of a severe frontal collision of the vehicle, for example, they swing through with their head between the front seat rests and can strike parts of the fittings hard in a kind of jack-knife effect.
To prevent this, in a known safety device of the type initially described in German Published Unexamined Application No. (DE-OS) 2,058,608, two inflatable gas cushions, so-called air bags, known per se, are arranged in the top region of the back-rests of both the front seats beneath the head-rests so that in the inflated state the mutually facing surfaces of the two gas cushions touch each other. At least the upper region of the gap between the back-rests of the front seats is virtually closed by this means, and protection of the rear passenger in the central rear seat position against plunging through is achieved. The gas cushions are inflated abruptly in the case of a crash, in known manner, the case of a crash being signaled by a deceleration sensor.
Known seat configurations of the front seats provide a pivotable arm-rest, also called a central arm-rest, between the front seats. Thus in the front seats known from German Pat. No. (DE-PS) 1,680,081 the arm-rests are fastened on the rear section of a box-shaped intermediate cushion which is inserted into a storage tray arranged on the transmission tunnel. In the case of other front seats the arm-rest is retained pivotably on the back-rests on one of the two front seats.
An underlying object of the invention is to develop a safety device of the type initially stated, including the arm-rest between the front seats, which effectively protects the rear passenger occupying the central rear seat position from serious injury in the case of a crash.
The object is achieved according to the invention, in a safety device of the above noted type by providing a pivoting drive to pivot the arm rest into a position cushioning the back seat passenger movement in the event of a predetermined vehicle deceleration.
In the safety device according to the invention, in the case of a crash the upholstered arm-rest is erected by sensor control and pivoted into a favorable position for the rear passenger secured by the pelvic belt in the central rear seat position in the case of a collision. By this means, on the one hand the head of the rear passenger who is thrown forward is intercepted favorably, and on the other hand his thorax is prevented from plunging between the back-rests of the front seats, so that a rotation of the thorax associated therewith is also eliminated. Injuries even of a minor nature can be totally prevented by a largely energy-dissipating construction of the arm-rest, as a large-area element for example. The arm-rest is fastened stably in its pivot axis and is preferably locked in its collision position by the pivoting drive, so that it cannot yield as a unit when struck by the head.
A favorable collision situation for the occupant's head and thorax is achieved by an additional air bag on the arm-rest, which is tripped simultaneously with its pivoting or just afterwards, because the inflating air bag moves to meet the thorax.
An occupation detector which senses the occupation of the central rear seat position according to certain preferred embodiments can cause the safety device to react only when this seat is actually occupied and it is therefore necessary to protect the rear passenger sitting there.
Pyrotechnical drives, such as are known from so-called belt tensioners for safety belts, are particularly suitable as pivoting drives; they trip virtually without delay and drive a traction cable which is connected to the arm-rest at high speed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.